Genus (Animalia): Bubo

The American (North and South America) horned owls and the Old World eagle-owls make up the genus Bubo, at least as traditionally described. The genus name Bubo is Latin for the Eurasian eagle-owl.

This genus, depending on definition, contains about one or two dozen species of typical owls (family Strigidae) and is found in many parts of the world. Some of the largest living Strigiformes are in Bubo. Traditionally, only owls with ear-tufts were included in this genus, but that is no longer the case.

Systematics

Systematics of which species to include among the horned owls is in an upheaval at present. While Mitochondrial DNA (mtDNA) cytochrome b sequence data favors the decision by some to regard the snowy owl as an eagle-owl adapted to Arctic conditions, moving it into Bubo,; this is not accepted by all authorities, many still preferring Nyctea.

Likewise disagreement exists over the decision by some to move the four fish-owls previously in the genus Ketupa provisionally into Bubo as well, which introduces a good bit of confusion. While the mtDNA cytochrome b data suggests that in this case, to make Bubo monophyletic the Scotopelia fishing owls would also need to be included there. On the other hand, the genus then becomes quite large and ill-defined, and Bubo in the expanded sense seems to consist of two distinct clades. Thus, the fish and fishing owls can alternatively be united in Ketupa if some aberrant eagle-owls – at least the barred, spot-bellied and Usambara eagle-owls, perhaps also Fraser's eagle-owl and maybe others – are moved into that genus too. As some enigmatic eagle-owls remain essentially unstudied and others – e.g. Verreaux's eagle-owl – are of unresolved relationships, more research is needed

Reference: Wikipedia